NO. II LARVAE OF THE ELATERID BEETLES GLEN 165 



are believed to be reliably named. The larvae regarded as L. cctypus 

 (Say) and L. anccps LeConte have been identified provisionally on 

 the basis of geographic distribution and field association with adults 

 of these species. Considerable uncertainty surrounds the identification 

 of the larvae here designated as suhauratus LeConte and occidentaUs 

 Candeze. The following changes might be in order: L. suhauratus 

 changed to infuse at us Motschulsky and occidentaUs changed to suh- 

 auratus LeConte. However, the names used in the present discussion 

 are those that were found on the labels accompanying the specimens 

 examined. 



The canus group includes some of the most important pest species 

 in America. All are soil inhabiting and all have been reported as injur- 

 ing cultivated plants. With reference to the Pacific coast species, 

 Lane (1935, p. 530) reports that the larvae inhabit moist soils, such as 

 stream margins, low-lying lands, and irrigated fields, and thrive espe- 

 cially in alkaline areas. Similar habits have been observed for the 

 larvae of "Limonius sp. near ectypus (Say)" occurring in the Prairie 

 Provinces. The eastern species also are known to inhabit moist areas, 

 but frequently are taken from sandy soils that are relatively well 

 drained. 



Very little has been published on the life history of these species, 

 but it appears that pupation normally occurs in late July or early 

 August, with the adults overwintering in their pupal chambers. 



The morphology of the larva of L. canus LeConte has been studied 

 in detail by Lanchester (1939). 



Larvae of the canus group differ from other known Limonius 

 larvae in that the prongs of the urogomphi are subequal in length. 

 This group is further characterized as follows : Relatively large 

 larvae, sometimes attaining 25 mm. in length when mature ; each 

 paranasal lobe with a cluster of 12 or more "sensory" pores (pnlp, 

 fig. 32, a) ; eyes absent ; with i small seta on ventral aspect of basal 

 segment of labial palpus ; maxillary palpus with second segment 

 longest ; 6 to 12 spinelike setae on each episternum of mesothorax and 

 metathorax ; abdominal mediotergites with prominent posterior setae 

 arranged in pairs (fig. 32, c) ; dorsal plate of ninth abdominal seg- 

 ment (figs. II, ^r; 32, d, f) with 2 or 4 unpaired setae, without medio- 

 dorsal groove (sometimes with shallow subcircular depression), and 

 with well-rounded "teeth" {to) or tubercles on lateral margins; in 

 ninth abdominal segment the distance between caudal notch and pleural 

 area approximates one-sixth total length of segment, exclusive of uro- 

 gomphi. 



